Noise reduction mechanism, noise reduction control method and range hood using the noise reduction mechanism

Abstract

The present invention relates to a noise reduction mechanism, a noise reduction control method, and a range hood using the noise reduction mechanism. The noise reduction mechanism includes a cavity formed in the range hood, an active noise reduction device, a first distance sensor, a second distance sensor, a microphone sensor, a controller, and a driving device. The range hood cavity includes a first cavity and a second cavity that can move up and down relative to the first cavity. The first cavity and the second cavity are arranged to be vertically connected, and the driving device drives the second cavity to move up and down relative to the first cavity. By setting the range hood cavity to be vertically connected and allowing the second cavity to move up and down relative to the first cavity under the drive of the driving device, the spatial size of the range hood cavity is changed, and then based on the detected sound pressure value of the noise signal generated by the range hood, the second cavity is adjusted to move to the optimal position to match the actual installation environment of the range hood, and then active noise reduction is performed to achieve an active noise reduction effect that maximizes the noise signal generated by the range hood.

Description

Technical Field

[0001] The present invention relates to the field of range hoods, and in particular to a noise reduction mechanism, a noise reduction control method, and a range hood having the noise reduction mechanism. Background Art

[0002] Currently, active noise reduction methods are usually used to reduce the impact of noise when a range hood (also referred to as a range hood) is in operation.

[0003] Chinese invention patent application CN107166458A discloses a range hood with active noise reduction, including a sound collection device and a sound generating device. The sound collection devices are distributed on the left and right sides of the range hood fan, and the sound generating device is integrated on the left and right sides below the range hood fan; the sound collection device is composed of a sound collection device cavity, a high-frequency broadband noise sound-absorbing sponge and a reference sensor; the sound generating device is composed of a sound generator cavity, a sound generator cover, a sound generator high-frequency sound-absorbing sponge and a speaker; an ANC signal control sounder is placed in the sound generator cavity of the sound generating device, the ANC signal control sounder is wired to the reference sensor, and the ANC signal control sounder is wired to the speaker through D / A conversion. This device can filter out broadband noise in high frequencies, effectively preventing the influence of oil smoke on the components in the device. In this system method, the generating device for generating the reverse waveform is a sound-generating device with a resonance cavity. This device filters out broadband noise in high frequencies of the sound generated by the loudspeaker, retaining only the linear spectrum in low and high frequencies, effectively solving the interference problem between the reverse broadband noise in the sound field and the linear sound field of the source sound field, and avoiding the system stability problem caused by the poor timeliness of the broadband ANC system.

[0004] Separately, Chinese invention patent application CN108167910A provides an active noise reduction device and a range hood. Specifically, the active noise reduction device is positioned between the fan unit and the grille and includes a resonance chamber and a speaker. An oil passage is provided in the resonance chamber, allowing contaminated oil from the fan unit to drip onto the resonance chamber, where it is then directed through the oil passage into the housing unit and into the oil cup. This alleviates the poor noise reduction and oil dripping and leakage issues of prior art noise reduction devices.

[0005] However, the noise reduction methods for the noise generated by the range hoods in the above two invention patent applications still belong to the traditional active noise reduction methods. The noise they target is a fixed noise source, and the range hood needs to provide a cavity that is large enough and has a fixed space to place the active noise reduction device that performs the active noise reduction method. As a result, the space of the cavity cannot be adjusted, and the noise reduction needs of the range hood in different installation environments cannot be met when its cavity is limited. Summary of the Invention

[0006] The first technical problem to be solved by the present invention is to provide a noise reduction mechanism that can adjust the size of the range hood cavity space to match the noise reduction processing of the active noise reduction device in response to the above-mentioned prior art.

[0007] The second technical problem to be solved by the present invention is to provide a noise reduction control method for the above-mentioned noise reduction mechanism.

[0008] The third technical problem to be solved by the present invention is to provide a range hood using the above-mentioned noise reduction mechanism.

[0009] The technical solution adopted by the present invention to solve the first technical problem is: a noise reduction mechanism, comprising:

[0010] a range hood cavity formed on the range hood;

[0011] An active noise reduction device, comprising a microphone for collecting noise signals generated by the range hood and a speaker for playing a noise canceling signal to eliminate the noise signals, wherein the microphone is arranged outside the range hood cavity and the speaker is arranged inside the range hood cavity;

[0012] The range hood cavity includes a first cavity and a second cavity that can move up and down relative to the first cavity, and the first cavity and the second cavity are vertically connected; and the noise reduction mechanism further includes:

[0013] The first distance sensor detects the positive movement distance of the second cavity in the direction of increasing the size of the range hood cavity space;

[0014] a second distance sensor, for detecting the distance between the front end surface of the second cavity and a preset reference surface when the second cavity moves;

[0015] A microphone sensor is provided at the air inlet of the range hood to detect the sound pressure value of the noise signal generated by the range hood;

[0016] The controller is connected to the microphone, the speaker, the first distance sensor, the second distance sensor and the microphone sensor respectively;

[0017] The driving device is connected to the controller and drives the second cavity to move up and down relative to the first cavity under the control of the controller.

[0018] Improved, in the noise reduction mechanism, the first cavity is located above the second cavity, and the preset reference plane is the upper surface of the stove.

[0019] As another arrangement of the first cavity and the second cavity, optionally, in the noise reduction mechanism, the first cavity is located below the second cavity, and the preset reference plane is the ceiling or ceiling above the range hood.

[0020] Furthermore, in the noise reduction mechanism, the driving device includes:

[0021] A lifting rod is fastened to the second cavity;

[0022] The motor drives the lifting rod, and the motor is connected to the controller.

[0023] The technical solution adopted by the present invention to solve the second technical problem is: a noise reduction control method, using the noise reduction mechanism, characterized in that it includes the following steps:

[0024] Step S1, a microphone sensor detects a first sound pressure value of a noise signal generated by a range hood;

[0025] Step S2: the controller controls the driving device to drive the second cavity to move forward in a direction of increasing the size of the range hood cavity, and the first distance sensor detects the forward movement distance of the second cavity;

[0026] Step S3: The controller makes a judgment based on the total distance of the second cavity moving forward:

[0027] When the total distance value reaches the preset distance value, the driving device is controlled to temporarily stop driving the second cavity to move forward, and the process goes to step S4; otherwise, the process goes to step S2;

[0028] Step S4, the microphone sensor again detects a second sound pressure value of the noise signal generated by the range hood;

[0029] In step S5, the controller makes a judgment based on the sound pressure difference between the first sound pressure value and the second sound pressure value of the noise signal detected by the microphone sensor:

[0030] When the sound pressure difference is greater than or equal to the preset difference, the driving device is controlled to stop driving the second cavity to move forward, and the active noise reduction device is controlled to perform the active noise reduction processing operation; otherwise, the process proceeds to step S6;

[0031] Step S6: Detecting the spacing distance between the front end surface of the second cavity and the preset reference plane when the second cavity moves, calculating the difference between the spacing distance and the preset spacing distance, and making a judgment based on the difference:

[0032] When the difference is greater than or equal to the preset interval distance difference, go to step S2; otherwise, go to step S7;

[0033] In step S7, the controller takes the position of the second cavity corresponding to the maximum value of the sound pressure difference between the first sound pressure value and the second sound pressure value of the noise signal detected by the microphone sensor as the optimal position, and controls the driving device to drive the second cavity to move to the optimal position, and then controls the active noise reduction device to perform the active noise reduction processing operation.

[0034] The technical solution adopted by the present invention to solve the third technical problem is: a range hood, characterized in that it applies any one of the noise reduction mechanisms described above.

[0035] Compared with the prior art, the advantages of the present invention are:

[0036] First, in the noise reduction mechanism of the invention, the range hood cavity is set to be a first cavity and a second cavity that are set to penetrate each other vertically, and the second cavity can be driven by a driving device to move up and down relative to the first cavity, thereby continuously changing the space size of the entire range hood cavity, and then adjusting the second cavity to move to the optimal position based on the detected sound pressure value of the noise signal generated by the range hood, and then the active noise reduction device performs active noise reduction processing to match the actual installation environment of the range hood, thereby achieving an active noise reduction effect that maximizes the noise signal generated by the range hood.

[0037] Secondly, in the noise reduction method of the invention, the noise signal generated by the range hood is detected and processed to continuously adjust the moving distance of the second cavity relative to the first cavity, thereby changing the spatial size of the entire range hood cavity. After the second cavity moves to the optimal position, the active noise reduction processing operation is performed to achieve the active noise reduction effect of maximizing the noise signal generated by the range hood while matching the actual installation environment of the range hood. BRIEF DESCRIPTION OF THE DRAWINGS

[0038] Figure 1 This is a schematic diagram showing the connections of the main functional components of the noise reduction mechanism in the first embodiment of the present invention;

[0039] Figure 2 This is a structural diagram of a range hood in Embodiment 1 of the present invention;

[0040] Figure 3 for Figure 2 The schematic diagram of the range hood in the actual installation environment is shown;

[0041] Figure 4 This is a schematic diagram of the first cavity and the second cavity after assembly in Example 1 of the present invention;

[0042] Figure 5 Schematic diagram of the noise reduction control method of the noise reduction mechanism in the first embodiment of the present invention;

[0043] Figure 6 Schematic diagram of the state of the range hood in the second embodiment of the present invention under actual installation environment. DETAILED DESCRIPTION

[0044] The present invention will be described in further detail below with reference to the accompanying drawings and embodiments.

[0045] Example 1

[0046] This embodiment provides a noise reduction mechanism applicable to a range hood, which is used to reduce the noise generated by the range hood during operation. Figures 1 to 4 As shown, the noise reduction mechanism in this embodiment includes a range hood cavity 1 and an active noise reduction device. The range hood cavity 1 is formed on the range hood. The range hood cavity 1 is formed by a first cavity 11 and a second cavity 12 which are arranged through from top to bottom. The first cavity 11 is located at the top and the second cavity 12 is located below the first cavity 11. The active noise reduction device has a microphone 21 for collecting the noise signal generated by the range hood and a loudspeaker 22 for playing a noise reduction signal to eliminate the noise signal. The microphone 21 is arranged on the outside of the range hood cavity 1 and the loudspeaker 22 is arranged on the inside of the range hood cavity 1; moreover, the noise reduction mechanism of this embodiment also includes a first distance sensor 23, a second distance sensor 24, a microphone sensor 25, a controller 26 and a driving device 27 which drives the second cavity 12 to move up and down relative to the first cavity 11 under the control of the controller 26. The controller 26 is respectively connected to the microphone 21, the loudspeaker 22, the first distance sensor 23, the second distance sensor 24, the microphone sensor 25 and the driving device 27. The driving device 27 can be arranged in a variety of ways. See also Figure 2 and Figure 3 As shown, the drive device 27 comprises a lifting rod 271 and a motor 272. The lifting rod 271 is secured to the second cavity 12. The motor 272 is connected to the controller 26 and is operatively coupled to the lifting rod 271. Thus, upon activation, the lifting rod 271 is driven by the motor 272 to move upward and downward, thereby driving the second cavity 12 up and down relative to the first cavity 11. In this embodiment, movement of the second cavity 12 in a direction that increases the size of the range hood cavity 1 is defined as positive movement. A first distance sensor 23, located at the end of the lifting rod 271, detects the distance traveled by the second cavity 12 in this direction. A second distance sensor 24 detects the distance between the front end surface S0 of the second cavity 12 during movement and a predetermined reference plane S, which in this case is the upper surface of the stovetop. The second distance sensor 24 can be located on the front end surface S0 of the second cavity 12 during movement. The microphone sensor 25 is disposed at the air inlet of the range hood to detect the sound pressure value of the noise signal generated by the range hood. For example, the microphone sensor 25 is disposed on the air inlet plate of the range hood.

[0047] In this embodiment, the vertical distance between the air outlet plate 31 and the preset reference plane S is set to d1, and the vertical height between the air outlet plate 31 and the air outlet cover 32 is d0, wherein 5 cm ≤ d1 - d0 ≤ 10 cm.

[0048] In addition, this embodiment also provides a range hood. Specifically, the range hood is applied with the above-mentioned noise reduction mechanism.

[0049] The following combination Figures 1 to 5 , the noise reduction control method of the noise reduction mechanism in this embodiment is described. Specifically, the noise reduction control method includes the following steps:

[0050] Step S1, the microphone sensor 25 detects a first sound pressure value of a noise signal generated by the range hood; wherein the first sound pressure value here is marked as P1;

[0051] In step S2, the controller 26 controls the driving device 27 to drive the second cavity 12 downward, and the second distance sensor 24 detects the movement distance of the second cavity 12. Assume that the movement distance of the second cavity 12 is d1. The direction of the downward movement of the second cavity 12 is the direction of increasing the size of the range hood cavity 1. In this embodiment, the movement of the second cavity in the direction of increasing the size of the range hood cavity is defined as positive movement.

[0052] In step S3, the controller 26 makes a judgment based on the total distance the second cavity 12 moves downward:

[0053] When the total distance value reaches the preset distance value, the control driving device 27 temporarily stops driving the second cavity to move downward, for example, pausing for 2 seconds, and then proceeds to step S4; otherwise, proceeds to step S2; wherein, the controller 26 can calculate the total distance value of the second cavity 12 moving downward according to the moving distance of the second cavity 12 detected by the second distance sensor 24; that is, assuming that the preset distance value here is D TH , for example, the preset distance value D TH Set to 5cm; the total distance the second cavity 12 moves downward is marked as D;

[0054] Step S4, the microphone sensor 25 detects again the second sound pressure value of the noise signal generated by the range hood; wherein the second sound pressure value here is marked as P2;

[0055] In step S5, the controller 26 makes a judgment based on the sound pressure difference between the first sound pressure value P1 and the second sound pressure value P2 of the noise signal detected by the microphone sensor 25:

[0056] When the sound pressure difference is greater than or equal to the preset difference, indicating that the second cavity 12 has moved to the current position, the controller 26 controls the driving device 27 to stop driving the second cavity downward and controls the active noise reduction device to perform the active noise reduction processing operation; otherwise, the process proceeds to step S6; wherein the sound pressure difference between the first sound pressure value P1 and the second sound pressure value P2 is marked as ΔP, ΔP = P2-P1;

[0057] Step S6: Detect the spacing distance L between the front end surface S0 of the second cavity 12 and the preset reference surface S when the second cavity 12 moves, and calculate the spacing distance L and the preset spacing distance L. TH The difference between △L, △L=LL TH , and make a judgment based on the difference:

[0058] When the difference ΔL is greater than or equal to the preset difference, it indicates that the downward distance of the second cavity 12 is still small, and the process proceeds to step S2; otherwise, it indicates that the downward distance of the second cavity 12 has reached the requirement, and the process proceeds to step S7;

[0059] In step S7, the controller takes the position of the second cavity corresponding to the maximum value of the sound pressure difference between the first sound pressure value and the second sound pressure value of the noise signal detected by the microphone sensor as the optimal position, and controls the driving device to drive the second cavity to move to the optimal position, and then controls the active noise reduction device to perform the active noise reduction processing operation.

[0060] For example, assuming that the position of the second cavity corresponding to the maximum value of the sound pressure difference between the first sound pressure value and the second sound pressure value of the noise signal detected by the microphone sensor 25 is the position G when the total distance the second cavity 12 moves downward is D', then the controller 26 at this time controls the driving device 27 to drive the second cavity 12 to move to the optimal position G, and controls the active noise reduction device to perform active noise reduction processing operations.

[0061] This embodiment arranges the range hood cavity into a first cavity and a second cavity which are arranged to penetrate each other vertically, and enables the second cavity to move up and down relative to the first cavity under the drive of a driving device, thereby continuously changing the spatial size of the range hood cavity, and then adjusts the second cavity to move to the optimal physical noise reduction position based on the detected sound pressure value of the noise signal generated by the range hood to match the actual installation environment of the range hood, and then the active noise reduction device performs active noise reduction processing to achieve an active noise reduction effect that maximizes the noise signal generated by the range hood.

[0062] Example 2

[0063] This embodiment provides another noise reduction mechanism suitable for use with a range hood, which reduces the noise generated by the range hood during operation. This mechanism differs from the noise reduction mechanism in the first embodiment in that the first cavity 11 in this embodiment is located below, and the second cavity 12 is located above the first cavity 11. Furthermore, the preset reference surface S in this embodiment is the ceiling or suspended ceiling above the range hood.

[0064] In addition, this embodiment also provides a range hood. Specifically, the range hood is applied with the above-mentioned noise reduction mechanism.

[0065] See also Figure 6 As shown, the difference from the noise reduction control method in Example 1 is that when the noise reduction control method in Example 2 executes step S6, the detected spacing distance is the distance between the front end surface of the second cavity 12 when it moves and the ceiling or ceiling above the range hood as the preset reference plane S. The remaining control steps can refer to those described in Example 1 and will not be repeated here.

Claims

1. Noise reduction mechanism, including: A range hood cavity (1) is formed on the range hood; An active noise reduction device comprises a microphone (21) for collecting a noise signal generated by a range hood and a loudspeaker (22) for playing a noise canceling signal for eliminating the noise signal, wherein the microphone (21) is arranged outside a range hood cavity (1), and the loudspeaker (22) is arranged inside the range hood cavity (1); The range hood cavity (1) is characterized in that it comprises a first cavity (11) and a second cavity (12) capable of moving up and down relative to the first cavity (11), and the first cavity (11) and the second cavity (12) are arranged to be vertically connected; and the noise reduction mechanism further comprises: A first distance sensor (23) detects a positive movement distance of the second cavity (12) in a direction of increasing the size of the range hood cavity (1); A second distance sensor (24) detects the distance between the front end surface of the second cavity (12) and a preset reference surface when the second cavity (12) moves; wherein the second distance sensor (24) is arranged on the front end surface of the second cavity (12) when the second cavity (12) moves; A microphone sensor (25) is provided at the air inlet of the range hood to detect the sound pressure value of the noise signal generated by the range hood; a controller (26) connected to the microphone (21), the speaker (22), the first distance sensor (23), the second distance sensor (24) and the microphone sensor (25); a driving device (27) connected to the controller (26), wherein the driving device (27) drives the second cavity (12) to move up and down relative to the first cavity (11) under the control of the controller (26); The noise reduction control method of the noise reduction mechanism includes the following steps: Step S1, a microphone sensor detects a first sound pressure value of a noise signal generated by a range hood; Step S2: the controller controls the driving device to drive the second cavity to move forward in a direction of increasing the size of the range hood cavity, and the first distance sensor detects the forward movement distance of the second cavity; Step S3: The controller makes a judgment based on the total distance of the second cavity moving forward: When the total distance value reaches the preset distance value, the driving device is controlled to temporarily stop driving the second cavity to move forward, and the process goes to step S4; otherwise, the process goes to step S2; Step S4, the microphone sensor again detects a second sound pressure value of the noise signal generated by the range hood; In step S5, the controller makes a judgment based on the sound pressure difference between the first sound pressure value and the second sound pressure value of the noise signal detected by the microphone sensor: When the sound pressure difference is greater than or equal to the preset difference, the driving device is controlled to stop driving the second cavity to move forward, and the active noise reduction device is controlled to perform the active noise reduction processing operation; otherwise, the process proceeds to step S6; Step S6: Detecting the spacing distance between the front end surface of the second cavity and the preset reference plane when the second cavity moves, calculating the difference between the spacing distance and the preset spacing distance, and making a judgment based on the difference: When the difference is greater than or equal to the preset interval distance difference, go to step S2; otherwise, go to step S7; In step S7, the controller takes the position of the second cavity corresponding to the maximum value of the sound pressure difference between the first sound pressure value and the second sound pressure value of the noise signal detected by the microphone sensor as the optimal position, and controls the driving device to drive the second cavity to move to the optimal position, and then controls the active noise reduction device to perform the active noise reduction processing operation.

2. The noise reduction mechanism according to claim 1, characterized in that: The first cavity (11) is located above the second cavity (12), and the preset reference plane is the upper surface of the stove.

3. The noise reduction mechanism according to claim 1, characterized in that: The first cavity (11) is located below the second cavity (12), and the preset reference plane is a suspended ceiling or a ceiling above the range hood.

4. The noise reduction mechanism according to any one of claims 1 to 3, characterized in that: The driving device comprises: A lifting rod (271) is fixedly mounted on the second cavity (12); The motor (272) drives the lifting rod (271), and the motor (272) is connected to the controller (26).

5. A noise reduction control method, using the noise reduction mechanism according to any one of claims 1 to 4, characterized in that: The steps include: Step S1, a microphone sensor detects a first sound pressure value of a noise signal generated by a range hood; Step S2: the controller controls the driving device to drive the second cavity to move forward in a direction of increasing the size of the range hood cavity, and the first distance sensor detects the forward movement distance of the second cavity; Step S3: The controller makes a judgment based on the total distance of the second cavity moving forward: When the total distance value reaches the preset distance value, the driving device is controlled to temporarily stop driving the second cavity to move forward, and the process goes to step S4; Otherwise, go to step S2; Step S4, the microphone sensor again detects a second sound pressure value of the noise signal generated by the range hood; In step S5, the controller makes a judgment based on the sound pressure difference between the first sound pressure value and the second sound pressure value of the noise signal detected by the microphone sensor: When the sound pressure difference is greater than or equal to a preset difference, the driving device is controlled to stop driving the second cavity to move forward, and the active noise reduction device is controlled to perform an active noise reduction processing operation; Otherwise, go to step S6; Step S6: Detecting the spacing distance between the front end surface of the second cavity and the preset reference plane when the second cavity moves, calculating the difference between the spacing distance and the preset spacing distance, and making a judgment based on the difference: When the difference is greater than or equal to the preset interval distance difference, go to step S2; otherwise, go to step S7; In step S7, the controller takes the position of the second cavity corresponding to the maximum value of the sound pressure difference between the first sound pressure value and the second sound pressure value of the noise signal detected by the microphone sensor as the optimal position, and controls the driving device to drive the second cavity to move to the optimal position, and then controls the active noise reduction device to perform the active noise reduction processing operation.

6. A range hood, characterized in that: The noise reduction mechanism according to any one of claims 1 to 4 is used.

Images